The Siemens SIRIUS 3RT1944-5AR61 is a magnet coil for Size S3 contactors, rated 400 V AC at 50 Hz and 440 V AC at 60 Hz, with a screw terminal connection. The coil's operating range at 50 Hz is 0.8 to 1.1 times the rated voltage, meaning it holds in reliably down to 320 V and picks up consistently across a 15% tolerance band — useful for lines with brownout conditions or long control-wire runs.
This coil is marked as a phased-out product. The official successor is the SIRIUS 3RT2 series.
The coil mounts onto the SIRIUS Size S3 contactor via screw terminals. The AC control supply voltage is fixed at 400 V (50 Hz) / 440 V (60 Hz) — no dual-voltage tap or DC variant. If the panel runs a 24 V DC control bus, this coil requires a separate AC supply or a relay interface.